The overall production cost is what Nvidia's desired sale price will scale with, and competition from AMD is what would make them shrink their margins. The soft cap on pricing is the point at which their sales slow to an unacceptable level.
Elaborating on point one above - If the production cost on Ampere was half that of Turing, Nvidia would cut prices (not by half, but by a fair degree, pocketing the rest in extra margin). They want to increase sales volume, one because it will produce higher overall profits to a certain point, and another because when the market expands, that's more people who will become future customers (if prices/margins go up again), and another because being a higher volume customer means better deals and preference from the foundries. Turing prices went up not because Nvid incerased margins on them dramatically, but because their production prices went up, and they wished to maintain roughly equivalent margin on them compared to Pascal. This meant depressed overall sales gen on gen.
Point two and three - Nvidia won't accept lower margins unless sales become totally unacceptable, or more likely until they are forced to in order to maintain a competitive position in the market versus AMD dGPUs. Nvidia will temporarily accept reduced profits in order to maintain market share (within an elastic threshold). But if their marketshare is not threatened, then they will instead keep raking in the cash.
The new consoles will not, themselves, cause them to drop their prices. If anything, anxiety surrounding the performance of the consoles will push more people to upgrade if they can.